Conventionally, there is some demand for a reduction in power consumption in display devices such as liquid crystal display devices. Accordingly, for example, Patent Document 1 discloses a display device drive method in which a scanning period (also called a refresh period) T1, in which screen refresh is performed by scanning gate lines of a liquid crystal display device, is followed by a pause period (no-refresh period) T2, in which the refresh is paused by stopping the scanning of all of the gate lines. For example, it is possible to make settings such that control signals are not provided to a gate driver and/or a source driver during the pause period T2. As a result, it is possible to pause the operation of the gate driver and/or the operation of the source driver, resulting in reduced power consumption. The drive performed with the refresh period followed by the no-refresh period, as in the drive method described in Patent Document 1, is called, for example, “pause drive”. Note that pause drive is also called “low-frequency drive” or “intermittent drive”. The pause drive as above is suitable for displaying still images. Besides Patent Document 1, for example, Patent Documents 2 to 5 disclose inventions relevant to pause drive.
Incidentally, there is a known function of generating video data on the basis of frame image data and providing display based on the video data. Such a function is called by different names depending on the types of video. A video which changes two-dimensionally in part or in whole or changes one-dimensionally in part is called an “animation video”, and the function of displaying an animation video is called, for example, an “animation function”. A video which repeats a one-dimensional change in whole is called, for example, a “rotation video”, and the function of displaying a rotation video is called, for example, a “rotation function”. It should be noted that such classification of video types is merely illustrative. With the animation function or the rotation function, it is possible to display a video loop readily without receiving image data externally.
For example, a display device with the animation function is capable of selectively displaying either an animation video or animation still images consisting of the same type of frame images from among a plurality of frame images that constitute the animation video. Hereinafter, where the animation video and the animation still images are not specifically distinguished from each other, they will be referred to as “animation images”. Moreover, for example, a display device with the rotation function is capable of selectively displaying either a rotation video or rotation still images consisting of the same type of frame images from among a plurality of frame images that constitute the rotation video. Hereinafter, where the rotation video and the rotation still images are not specifically distinguished from each other, they will be referred to as “rotation images”. Unless otherwise specified, the following descriptions will be directed mainly to the “animation function”. However, it should be noted that similar descriptions apply to the “rotation function”.